Came back to my parked car in this condition - no note left naturally. I have sourced a spare light cluster and will change that myself. For the body work I've been quoted £290 - is this a fair quote? Anyone tried a DIY approach before? 

How much of a perfectionist are you?

 

It looks to me (only going by the photos) that most of that will polish out using T-Cut.

 

It won't get it all as it looks as though there are some small areas where the paint has been removed, but if £290 is a lot of money for you then I'd definitely be investing £10 in a bottle of cutting polish and spending 30 minutes on it myself first.

 

If after the new rear light is fitted and after half an hour of vigorous wrist action doesn't get it as good as you want then still £290 sounds steep. Who was this quote from?

Yeah, I would say £200 max....and that would be on the high side. 

 

Given the location on the corner of the bumper someone like Chips Away or any other mobile repairer should be able to get that spot on.

That will t-cut out. Try that first, it's not a huge outlay for a tube of T-cut. I think you'll be surprised how much better it will look. In the end it's the bumper and they will get knocks over time (that's what they're designed for). I love my Octy to death, my favourite car ever (in nearly 40 years of driving) but it's not a Mk2 Jaguar or Aston Martin DB5, so I'm not that precious about it YMMV.